1. Field of the Invention
This invention relates to a cassette tape which contains a magnetic tape in a case for recording and reproducing and, more particularly, to a cassette tape capable of regulating a range of an object to be recorded and reproduced within a range of the length of its tape.
2. Description of Related Art
In conventional cassette tapes which include all ordinary type and endless type, the lengths of the respective tapes have been determined fixedly in response to recording and reproducing time, but the cassette tape itself could not be set or regulated in a range of the available length at all. In most of the conventional ordinary tape recorder/reproducer systems frequently used, the fact that the tape reached its end during recording or reproducing was detected according to the tension of the tape thereby to stop feeding of the tape or to automatically reversely feed the tape. In the systems of such a type, it was impossible to automatically stop feeding of the tape at its arbitrary position by designating in advance the arbitrary position of the tape or to automatically reversely feed the tape.
Therefore, if required recording time of the tape is different, another cassette tape having a different length must be employed, and, hence it was necessary to previously prepare various cassette tapes having a variety of lengths and to select any of the cassette tapes having the length of the tape which matches the required recording time for each time. However, the conventional cassette tapes sold in the general market are sorted according to the lengths of recording time, but the number of the types of the cassette tapes having different lengths is not so sufficient, and cannot respond to certain utility. As an example, in the case where training or learning of a foreign language is repeated by using cassette tapes, the lengths of phrases and sentences to be repeated include a number of kinds. Even if cassette tapes preferably responding to the training or learning of the language are desired to be selected, it is extremely rare to select the cassette tapes just in response to the required recording time. In the case of a cassette tape having a short length, an object to be recorded can fail to be sufficiently recorded on the tape, or in the case of a cassette tape having an excessively long length, an unrecorded portion of the tape remains, and a difficulty in the operation might frequently occur.
Even in the above cases, however, it is very difficult in techniques to prepare a variety of cassette tapes having a number of different lengths in response to objects to be presumed to be recorded, to measure required recording time at each time and to then select a suitable one from the various cassette tapes and to sequentially frequently exchange the tapes.